Abstract A starting circuit for high intensity discharge lamps supplied from an alternating current line through a ballast inductance, and in some cases a pulse transformer inductance, includes a surge voltage protector (SVP) or like voltage responsive, current switching gas breakdown device connected intermediate the end of the inductance, a capacitor connected to the lamp end of the inductance, the SVP and capacitor being connected in parallel with each other and in series with a resistance across the lamp so that upon breakdown of the device in each half AC cycle the capacitor discharges applying a voltage surge to the lamp stepped up through the inductance. The charge on the capacitor follows the ignition voltage required to start or reignite the lamp as the ignition voltage varies during the life of the lamp.
A starting circuit for a high intensity discharge lamp comprising: alternating current line terminals, lamp terminals having connections to the line terminals, at least one connection including an inductance, a voltage responsive current switching surge voltage protector breakdown device connected to the inductance intermediate its ends, said device having a switching time in the order of a microsecond, a capacitor and the breakdown device connected to each other through a portion of the inductance, and a resistance in series with the capacitor across the lamp terminals, wherein the inductance includes an inductive reactor and at least one winding of a pulse transformer connected between the reactor and one lamp terminal.
Claim 2
Dependent Claim
110 words
A starting circuit for a high intensity discharge lamp comprising: alternating current line terminals, lamp terminals having connections to the line terminals, at least one connection including an inductance, a voltage responsive current switching surge voltage protector breakdown device connected to the inductance intermediate its ends, said device having a switching time in the order of a microsecond, a capacitor and the breakdown device connected to each other through a portion of the inductance, and a resistance in series with the capacitor across the lamp terminals, wherein the inductance includes an inductive reactor and at least one winding of a pulse transformer connected between the reactor and one lamp terminal.
Claim 3
Dependent Claim
29 words
Apparatus according to claim 1 wherein the inductive reactor is sealed in a closed housing and the pulse transformer winding is connected in series therewith externally of the housing.